I told him that we have a special powder in Europe and other parts of the world. When the tiniest spark of fire touches a small heap of this powder it catches fire and explodes into the air as though it is as big as a mountain, making a noise like thunder. I also told him that a small heap of powder can be put into a tube of brass or iron, from which it can drive a ball of lead with such speed that nothing can stand in its way. The largest of these balls can sink a ship, destroy a town or wipe out whole ranks of soldiers.
I told the King that I knew how to make this powder
(я сказал королю, что знаю, как изготовить этот порошок) and that it didn't cost much money (и что это стоит недорого). I could also make the drawings (я также могу сделать чертежи) from which his workmen could make the tubes (по которым его мастера смогут изготовить стволы). I offered all this valuable knowledge to the King of Brobdingnag (все эти ценные знания/сведения я предложил королю Бробдингнага;The King was struck with amazement and horror at the very idea
(король пришел в изумление и ужас: «был поражен/охвачен изумлением и ужасом» от самой =valuable ['væljuəb(ə)l], knowledge ['nɔlɪdʒ], waste [weɪst]
I told the King that I knew how to make this powder and that it didn't cost much money. I could also make the drawings from which his workmen could make the tubes. I offered all this valuable knowledge to the King of Brobdingnag in return for the kindness he had shown me.
The King was struck with amazement and horror at the very idea. How could I stand there describing scenes of blood, death and waste, as though I were doing him a favour! (These were his very words.) He would prefer to lose half his kingdom than be given such a secret.
This is the same King
(/и/ это тот самый король) who is considered by his own people to be learned and wise (который считается своим народом =